Disc and sidebar cylinder lock

ABSTRACT

Tumbler discs are supported within a cylinder for rotation therein between locked and unlocked positions. The cylinder itself is rotatably supported within an outer casing into which it may be loaded from the front and held in place by a hidden externally-threaded collar. When the tumbler discs are in the locked position, they support a locking bar in engagement with a slot in the cylinder and an aligned groove in the outer casing to prevent the cylinder from being rotated relative to the outer casing. The first tumbler disc may include a concentric portion of reduced diameter and increased thickness communicating with the front of the outer casing and serving as a freely rotatable spinner until a key is engaged with the tumbler discs. Driving portions of the key are angularly coded for rotating the tumbler discs to the unlocked position as the key is turned in one direction. When the tumbler discs are in the unlocked position, peripheral lugs on some of the tumbler discs are positioned in abutment upon a stop portion of the cylinder, and notches in all of the tumbler discs are aligned with the slot in the cylinder to form a groove for receiving the locking bar so that the cylinder and the tumbler discs may be freely rotated together relative to the outer casing as the key is turned further in the same direction. In the unlocked position one of the tumbler discs may be releasably engaged with the cylinder so that the cylinder and tumbler discs may also be freely rotated together relative to the outer casing as the key is turned in the opposite direction. This same tumbler disc may be disengaged from the cylinder under control of the key. A locking member protruding through an opening in the rear of the outer casing is rotatably driven by the cylinder to lock and unlock a structure in which the outer casing is embedded.

United States Patent Prescott [54] DISC AND SIDEBAR CYLINDER LOCK [72] Inventor: Burnerd Clark Prescott, 440 Moffett Blvd., Mountain View, Calif. 94040 [22] Filed: March 30, 1970 [21] Appl. No.: 23,554

Primary Examiner-Robert L. Wolfe Attorney-Roland l. Griffin [5 7 ABSTRACT Tumbler discs are supported within a cylinder for rotation therein between locked and unlocked positions. The cylinder itself is rotatably supported within an outer casing into which it may be loaded from the front and held in place by a hidden extemallythreaded collar. When the tumbler discs are in the Oct. 3, 1972 locked position, they support a locking bar in engagement with a slot in the cylinder and an aligned groove in the outer casing to prevent the cylinder from being rotated relative to the outer casing. The first tumbler disc may include a concentric portion of reduced diameter and increased thickness communicating with the front of the outer casing and serving as a freely rotatable spinner until a key is engaged with the tumbler discs. Driving portions of the key are angularly coded for rotating the tumbler discs to the unlocked position as the key is turned in one direction. When the tumbler discs are in the unlocked position, peripheral lugs on some of the tumbler discs are positioned in abutment upon a stop portion of the cylinder, and notches in all of the tumbler discs are aligned with the slot in the cylinder to form a groove for receiving the locking bar so that the cylinder 29d the tumbler discs may-be freely rotated together relative to the outer casing as the key is turned further in the same direction. in the unlocked position one of the tumbler discs may be releasably engaged with the cylinder so that the cylinder and tumbler discs may also be freely rotated together relative to the outer casing as the key is turned in the opposite direction. This same tumbler disc may be disengaged from the cylinder under control of the key. A locking member protruding through an opening in the rear of the outer casing is ,rotatably driven by the cylinder to lock and unlock a structure in which the outer casing is embedded.

20 Claims, 25 Drawing Figures PATENTEUUET 3 I972 3.695.073

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igure 2 igure 8 PATENTEDUET 3 1912 SHEET 3 OF 7 PATENTED 31973 3.695.073

SHEET Q 0F 7 igure l6 SHEET 5 0F 7 PATENTEUUCI 3 I972 igure nrsc AND SIDEBAR CYLINDER LOCK BACKGROUND OF THE INVENTION This invention relates to key-controlled disc and sidebar cylinder locks in which a cylinder for driving a cam, a threaded lug, or some other such rotary locking member is rotatably driven by one or more tumbler discs when those tumbler discs are rotated to an unlocked position and then further rotated in the same direction.

Disc and sidebar cylinder locks are generally more pick resistant, more simple and dependable in function, less subject to wear, and capable of a greater range of combinations than most other types of locks. However, unlike combination, lever, and some other types of locks, conventional disc and sidebar cylinder locks typically cannot be freely turned an equal number of turns in opposite directions when mounted in place and unlocked. In some conventional disc and sidebar cylinder locks rotation of the cylinder is limited to less than one complete revolution in any direction. See, for example, U. S. Pat. No. 2,217,047, entitled LOCK and issued on Oct. 8, I940, to John W. Fitz Gerald. In still others the cylinder may be freely rotated in the same direction in which the tumbler discs are rotated to the unlocked position, but cannot be rotated more than one complete revolution in the opposite direction. See, for example, U. S. Pat. No. 2,613,528 entitled CYLINDER LOCK" and issued on Oct. 14, 1952 to Johannes E. Salmivuori. Thus, conventional disc and sidebar cylinder locks typically cannot be used in applications where, for example, the cylinder must drive a threaded lug or some other such rotary locking member requiring the same plural number of turns to lock as to unlock.

In conventional disc and sidebar cylinder locks the cylinder is typically loaded into the outer casing, or barrel, of the lock through an opening in the rear of the barrel. Since this opening must necessarily be as large in diameter as the cylinder itself and since the cylinder is normally merely held in place by a spring clip 'or the like, there is very little metal to prevent the lock from being circumvented by forcing the cylinder back out through the opening in the rear of the barrel. Furthermore, once these rear-loaded disc and sidebar cylinder locks are embedded in a vault or some other structure to be locked the cylinder and tumbler discs often cannot be easily replaced as required, for example, to change keys.

SUMMARY OF THE INVENTION The principal object of this invention is to provide an improved disc and sidebar cylinder lock in which the cylinder may be freely rotated an equal number of complete revolutions in opposite directions for driving a threaded lug or some other such rotary locking member requiring the same plural number of turns to lock as to unlock.

Another object of this invention is to provide an improved disc and sidebar cylinder lock in which the cylinder and tumbler discs may be loaded into the bar rel from the front of the barrel to facilitate making the lock more force resistant and to facilitate replacing the cylinder once the lock is embedded in the structure to be locked.

Still another object of this invention is to provide a more versatile, safe, and reliable disc and sidebar cylinder lock of reduced size.

A further object of this invention is to provide an improved key for use with key-controlled locks and particularly disc and sidebar cylinder locks.

These objects are accomplished according to the preferred embodiments of this invention by rotatably supporting a cylinder within the barrel of the lock. Tumbler discs are supported within the cylinder for key-controlled rotation therein between a locked position, at which a locking bar is supported on their peripheries and in engagement with a slot in the cylinder and an aligned groove in the barrel to prevent the cylinder from rotating relative to the barrel, and an angularIy-spaced unlocked position, at which notches in their peripheries are aligned with the slot in the cylinder to form a groove for completely receiving the locking bar to permit rotation of the cylinder relative to the barrel. One of the tumbler discs, whose angle of rotation between the locked and unlocked positions is not exceeded by any of the others, is provided with one or more lugs for releasably engaging the cylinder when the tumbler discs are rotated to the unlocked position. According to one of the preferred embodiments, this tumbler disc is provided with a pair of lugs for engaging corresponding notches in the cylinder when the tumbler discs are rotated to the unlocked position and the key is pulled forward. However, according to another of the preferred embodiments, this tumbler disc is provided with one lug and axially spring-loaded so that this lug is automatically engaged between a stop member and a stop portion of the cylinder when the tumbler discs are rotated to the unlocked position. In either case, engagement of this tumbler disc with the cylinder releasably locks all of the tumbler discs in the unlocked position for rotation with the cylinder so that the cylinder may be freely rotated with the tumbler discs an equal number of complete revolutions in opposite directions relative to the barrel. The tumbler discsmay be released from the unlocked position and returned to the locked position by simply pushing the key backward and rotating it toward the locked position, whereupon this same tumbler disc serves to help lift the locking bar back onto the peripheries of the tumbler discs and into engagement with the groove in the barrel to prevent the cylinder from being rotated relative to the barrel.

In accordance with one of the preferred embodiments, the multiple purpose tumbler disc described above is also employed as the first tumbler disc, provided with a concentric cylindrical key-receiving portion of reduced diameter and increased thickness communicating with the front of the barrel, and adapted to serve as a freely rotatable spinner when the key is removed. This significantly increases the resistance of the lock to drilling, forcing, and picking and thereby facilitates reducing the overall size of the lock without adversely affecting its strength and dependability. In accordance with the same embodiment, the cylinder is loaded into the barrel through an opening in the front of the barrel, axially slid into driving engagement with the head of a locking member extending through a smaller opening in the rear of the barrel, and held in place by a split externally-threaded collar that is hidden from view and can only be screwed into or out of place with the aid of the key. This front-loaded construction provides more metal at the rear of the barrel (thereby still further increasing the force-resistance of the lock), permits the cylinder to be easily replaced without removing the barrel from the structure in which it is embedded, and permits the cylinder to be automatically disengaged from the locking member as the cylinder is withdrawn from the barrel.

The key employed to actuate the lock has a straight end section of generally semicircular cross section with driving portions angularly coded for driving the tumbler discs between the locked and unlocked positions. It also has an intermediate section of larger cross section adjoining the main driving portion of the key and abutting upon the first tumbler disc when the key is fully inserted into the lock. This facilitates reducing the size of the key (and, hence, the size of the keyhole thereby still further increasing the pick resistance of the lock) without unduly weakening the key and permits the key to be used for forcing the tumbler discs axially backward within the cylinder in order to release them from rotational engagement with the cylinder in their unlocked position. In accordance with one of the preferred embodiments, the key further has a loopshaped end section of flattened cross section with one end resiliently separable from the other so that the key may be quickly and simply snapped onto a key ring.

Other and incidental objects of this invention will become apparent from a reading of this specification and an inspection of the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a frontloaded disc and sidebar cylinder lock and key according to one of .the preferred embodiments of this invention.

FIGS. 2 and 3 are cutaway perspective views taken from opposite sides of the lock of FIG. 1 when assembled and locked.

FIG. 4 is a front view of one of the tumbler discs employed in the lock of FIG. 1.

FIG. 5 is a front view of the first tumbler disc employed in the lock of FIG. 1.

FIG. 6 is a half-sectional side view of the first tumbler disc taken along the line 6-6 of FIG. 5.

FIG. 7 is a perspective view of the key of FIG. 1 as viewed from the opposite side and aligned for insertion into the lock when assembled and locked as viewed in FIG. 3.

FIG. 8 is an enlarged cross-sectional view of the key taken along the line 8-8 of FIG. 7.

FIG. 9 is a back end view of the cylinder employed in the lock of FIG. 1.

FIG. 10 is a half-sectional side view of the cylinder taken along the line 10-10 of FIG. 9.

FIG. 11 is a half-sectional side view of the lock of FIG. 1 when assembled, mounted in place, and locked with the key inserted.

FIG. 12 is a reduced cross-sectional view of the lock when assembled and locked taken along the line 12--- 12 of FIG. 11.

FIG. 13 is a half-sectional side view of the lock of FIG. I when assembled and unlocked.

FIG. 14 is a reduced cross-sectional view of the lock when assembled and unlocked taken along the line 1414 of FIG. 13.

FIGS. 15 and 16 are cutaway perspective views taken from opposite sides of the lock of FIG. 1 when assembled and unlocked.

FIG. 17 is a half-sectional side view of the lock of FIG. 1 when assembled and unlocked with the tumbler discs locked in the unlocked position for rotation with the cylinder and rotated with the cylinder in either a clockwise or a counterclockwise direction from the position shown in FIGS. 13-16.

FIG. 18 is a reduced cross-sectional view of the lock when assembled and unlocked taken along the line 18l8 of FIG. 17.

FIG. 19 is a cutaway perspective view of the lock of FIG. I when assembled and unlocked with the'tumbler discs locked in the unlocked position for rotation with the cylinder and rotated with the cylinder as shown in FIGS. 17-18.

FIG. 20 is an exploded perspective view of a rear- Ioaded disc and sidebar cylinder lock and key according to another of the preferred embodiments of this invention.

FIGS. 21 and 22 are cutaway and fragmentary perspective views, respectively, taken from opposite sides of the lock of FIG. 20 when assembled and locked.

FIGS. 23 and 24 are cutaway and fragmentary perspective views, respectively, taken from opposite sides of the lock of FIG. 20 when assembled and unlocked.

FIG. 25 is a perspective view of the key of FIGS. 20,

23, and 24 taken from the opposite side as shown in FIG. 20.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1-19, there is shown a disc and sidebar cylinder lock and key according to one of the preferred embodiments of this invention. As shown in FIGS. 1-6, this lock includes a plurality of tumbler discs 1-10. Each of these tumbler discs has a semicircular keyhole 12 and a circular outer periphery with a notch 14 therein. A round notch 14 is employed in each of the tumbler discs 2-9. Although a round notch 14 might also be employed in each of the tumbler discs 1 and 10, a rectangular notch 14 with its leading side 16 (as viewed in a clockwise direction) inclined at an angle of about 45 degrees is preferably employed. Notches 14 are arranged along the circular outer peripheries of tumbler discs 1-10 in a selected combination of different positions with respect to keyholes 12. A total of n different combinations is therefore possible, where n equals the number of possible notch positions and x equals the number of tumbler discs. Thus, for example, over a million different combinations may be provided by simply employing four possible notch positions (as illustrated by radial lines n,-,,, in FIG. 4) and ten different tumbler discs. For convenience in operating the lock these four possible notch positions are equally spaced along an arc of so that when keyholes 12 are aligned any combination of notches 14 may be brought into alignment by simply rotating each of the tumbler discs 1-10 through an angle of from O to 90 degrees.

Each of the tumbler discs 2-9 may also have one or more indentations 18 arranged at different positions around its circular outer periphery. These indentations are shallower than notches 14 and serve as false notches to increase the pick resistance of the lock. Each of the tumbler discs 2-10 has a lug 20 extending radially outward from its circular outer periphery. Lugs 20 are arranged along the circular outer peripheries of tumbler discs 2-10 at the same position (as illustrated by radial line 1 in FIG. 4) with respect to keyholes 12. The first tumbler disc 1 does not have a lug 20. However, it does have a concentric cylindrical front portion 22 of reduced diameter and increased thickness through which the corresponding keyhole 12 extends. It also has a pair of oppositely-facing semicircular lugs 24a and 24b adjoining its front face 26 and opposite sides of its cylindrical front portion 22. Lugs 24a and 24b do not extend axially along the full length of cylindrical front portion 22, or radially beyond the circular outer periphery, of the firsttumbler disc. They are arranged at diametrically opposite positions (as illustrated by radial lines 1 and l in FIG. 5), each angularly spaced 90 from notch position n Tumbler discs 1-10 have a locked position at which semi-circular keyholes 12 are aligned (see FIG. 1), lugs 20 are aligned (see FIG. 2), and notches 14 are scrambled in notch positions n according to a selected combination (see FIG. 3). In the illustrated combination of FIG. 3, notches 14 of tumbler discs 1, 2, and are in notch position n notches 14 of tumbler discs 4 and 8 are in notch position 11,, notch 14 of tumbler disc 6 is in notch position n;,, and notches 14 of tumbler discs 3, 5, 7, and 9 are in notch position n Tumbler discs l-l0 also have an unlocked position at which keyholes 12 and lugs 20 are misaligned (see FIG. 15) and notches 14 are unscrambled and aligned (see FIG. 16). For the illustrated combination of FIG. 3, tumbler discs 1-10 may be turned from the locked position to the unlocked position by rotating tumbler discs 1, 2, and 10 clockwise 90, rotating tumbler discs 4 and 8 clockwise 60, rotating tumbler disc 6 clockwise 30, and rotating tumbler discs 3, 5, 7, and 9 clockwise 0. Similarly, tumbler discs l-1.0 may be turned from the unlocked position to the locked position by rotating them counterclockwise through the same angles.

Tumbler discs 1-10 are turned between the locked and unlocked positions under the control of a key 28. As shown in FIGS. 1 and 7-8, key 28 has a straight end section 30 with a generally semicircular cross section corresponding to that of keyholes 12 so that the straight end section may be fully inserted into all of the keyholes when they are aligned. This straight end section includes a plurality of different driving portions 31-40 corresponding in order to tumbler discs 1-10. Each of these driving portions is angularly coded for driving the corresponding tumbler disc through the angle it must be rotated between the locked and unlocked positions as the key is turned through an angle of ninety degrees. As shown in FIG. 8, this is accomplished by providing driving portions 31-40 with a common radial rear driving surface d and by further providing each driving portion with a separate radial front driving surface d d d or (1., making an angle with respect to the plane of rear driving surface d (this is the angle at which each driving portion picks up its corresponding tumbler disc and is hereinafter referred to as the pick-up angle) equal to the complement of the angle through which the corresponding tumbler disc must be rotated between the locked and unlocked positions. Thus, for the combination illustrated in FIG. 3, driving portions 31, 32, and 40 each have a radial front driving surface a providing a pick-up angle of 0, driving portions 34 and 38 each have a radial front driving surface d providing a pick-up angle of 30, driving portion 36 has a radial front driving surface (1;, providing a pick-up angle of 60, and driving portions 33, 35, 37, and 39 each have a radial front driving surface d, providing a pick-up angle of The key 28 also has an intermediate section 42 with a circular cross section of the same diameter as straight end section 30. This intermediate section adjoins the main driving portion 31 of straight end section 30. Intermediate section 42 therefore provides the key with increased strength directly adjacent to the main driving portion 31 of the key. This facilitates reducing the size of the key without unduly weakening it, thereby permitting a reduction in the size of keyholes 12 and hence of the lock itself. Reducing the size of keyholes 12 also increases the pick resistance of the lock. When straight end section 30 of the key is fully inserted into keyholes 12 of tumbler discs 1-10, intermediate section 42 of the key abuts upon the face of cylindrical portion 22 of the first tumbler disc 1. This permits the key to be used for axially forcing the tumbler discs backward, thereby providing axial as well as rotational control of the tumbler discs. Key 28 further has a generally loop-shaped end section 44 of flattened cross section with one end 46 resiliently separable from the other so that the key may be quickly and simply snapped onto a key ring.

As shown in FIGS. 1-3 and 9-10, the lock also includes a cylinder 48 having a cylinder-shaped rear portion 50 for housing tumbler discs 1-10, a neck-like intermediate portion 52 of reduced diameter for supporting a split externally-threaded collar 54a and 54b with a smooth inner periphery so that intermediate portion 52 may be rotated therein, and a disc-shaped front portion 56 of increased diameter for hiding collar 54a and 54b when it is supported on intermediate portion 52. Rear portion 50 has a smooth axial cylindrical bore 58 for rotatably supporting tumbler discs 1-10. This bore is open at the back for receiving the tumbler discs and is closed at the front by an end wall 60. A concentric smooth axial cylindrical bore 62 of smaller diameter extends through front and intermediate portions 56 and 52 and end wall 60 of rear portion 50. This bore is provided for receiving and rotatably supporting cylindrical portion 22 of the first tumbler disc 1. A pair of oppositely facing semicircular notches 64a and 64b are also formed in end wall 60. These notches adjoin diametrically opposite sides of bore 62 and communicate with bore 58. They are positioned for receiving lugs 24a and 24b of the first tumbler disc 1 when it is rotated to the unlocked position and pulled forward. This permits the first tumbler disc 1 and the cylinder 48 to be releasably engaged for rotation together in either a clockwise or a counterclockwise direction.

A slot 66 extends through one side of rear portion 50 along the full length of bore 58. This slot is provided for receiving lugs 20 of tumbler discs 2-10. The edges 68a and 68b of slot 66 are disposed in the rotational paths of lugs 20 of tumbler discs 2-10 and are angularly spaced apart to serve as stops for limiting lugs 20 and, hence, tumbler discs 2-10 to rotation through a maximum angle of ninety degrees relative to cylinder 48.

Another slot 70 extends through the opposite side of rear portion 50 from end wall 60 to a location adjacent to the position of the last tumbler disc to be supported within bore 58. Slots 66 and 70 have a common plane of longitudinal symmetry orthogonally intersecting the common plane of radial symmetry of notches 64a and 64b along the common central axis of bores 58 and 62. Slot 70 is provided for receiving a cylindrical locking bar 72 supported on the circular outer peripheries of tumbler discs 1-2, 4, 6, 8, and 10 when the tum bler discs are rotated to the locked position and supported in a groove formed by alignment of notches 14 with slot 70 when the tumbler discs are rotated to the unlocked position. Locking bar 72 has a diameter substantially equal to, but not greater than, the depth of the groove formed by alignment of notches 14 with slot 70 so that the locking bar protrudes from slot 70 when supported on the circular outer peripheries of the tumbler discs but not when supported in this groove.

Tumbler discs 1-10 are separated from one another by annular washers 74 of the same outer diameter as the tumbler discs and are loaded with these washers into bore 58 through the open back end thereof so that when the tumbler discs are rotated to the locked position lugs 20 are aligned in abutment upon edge 68b of slot 66. Each washer 74 has a radial lug 75 that is fixedly engaged between edges 68a and 68b of slot 66. This prevents the washers from rotating and thereby prevents the rotational movement of any tumbler disc from being transmitted to the other tumbler discs. The outer peripheries of radial lugs 20 and 75 have a slightly smaller radius than the outer periphery of rear portion 50 so that they do not protrude therefrom. Each washer 74 also has an inner diameter greater than the diameter of semicircular keyholes 12 so as not to interfere with rotational or axial movement of straight end section 30 of key 28. In addition, each washer 74 has a notch 76 formed in its outer periphery to a depth as great as, or slightly greater than, notches 14 of tumbler discs 1-10. Notches 76 are positioned diametrically opposite lugs 75 and in alignment with slot 70 to prevent washers 74 from interfering with movement of locking bar 72 into the groove formed by alignment of notches 14 with slot 70 when the tumbler discs are rotated to the unlocked position. Tumbler discs l-l0 and washers 74 are held in bore 58 by a ring-shaped spacer 78 and a spring clip 80 that is seated in a groove 82 formed in the wall of bore 58 toward the open back end thereof.

As shown in F 108. 1-3, the lock also includes a locking member 84 that is rotatably driven by cylinder 48 to lock and unlock a structure in which the lock is embedded. This locking member may comprise, for example, a rotary locking lug formed with a circular head 86 of the same outer diameter as tumbler discs 1-10, with a radial lug 88 of the same radius and are as lugs 75 of washers 74, and with a partially-threaded cylindrical stem 90 of smaller diameter than head 86. Locking member 84 may therefore be releasably engaged for rotation with cylinder 48 by simply sliding head 86 into the open back end of bore 58 until head 86 abuts upon spring clip and lug 88 is fixedly engaged between edges 68a and 68b of slot 66. This type of driving engagement between the cylinder and locking member permits them to be quickly and simply disengaged without removing the locking member from a structure in which it is embedded.

As shown in FIGS. I-3 and 11, the lock further includes an outer casing or barrel 92. This barrel has an axial cylindrical bore 94 with an open front end through which cylinder 48 and locking member 84 may be loaded into the barrel, with a smooth front portion 96 of increased diameter for rotatably supporting discshaped front portion 56 of the cylinder, with a threaded intermediate portion 98 for threadedly engaging split externally-threaded collar 54a and 54b when it is supported on neck-like intermediate portion 52 of the cylinder, and with a smooth rear portion 100 for rotatably supporting cylinder-shaped rear portion 50 of the cylinder and head 86 of the locking member. The back end of bore 94 is closed by an end wall 102 with a partially tapered opening 104 of reduced diameter for receiving partially-threaded stem of the locking member and for rotatably seating a partially tapered portion of cylinder-driven head 86 of the locking member. End wall 102 is formed integrally with the rest of barrel 92 and with more metal than a'corresponding spring clip or the like to prevent cylinder 48 and locking member 84 from being forced out the back end of the barrel. A groove 106 is formed in the wall of bore 94 in communication with front portion 96 and along substantially the full length of intermediate and rear portions 98 and 100. This groove is made of a depth less than the diameter and about equal to the radius of locking bar 72. It is positioned for alignment with slot 70 in rear portion 50 of the cylinder to provide a channel for receiving locking bar 72 when the locking bar is supported on the circular outer peripheries of the tumbler discs. Engagement of locking bar 72 in aligned slot 70 and groove 106 prevents cylinder 48 from rotating relative to barrel 92.

Cylinder 48 and locking member 84 are mounted within barrel 92 by loading the locking member into bore 94 with partially-threaded stem 90 protruding through opening 104; by placing split extemallythreaded collar 54a and 5412 around neck-like intermediate portion 52 of the cylinder; by aligning a notch 107a in one side of collar portion 54a with a corresponding hole 107b extending through front portion 56 of the cylinder; by inserting a cylindrical pin into hole 107b and notch 107a to engage the externallythreaded collar for rotation with the cylinder; by fully inserting key 28 and turning it clockwise to rotate tumbler discs 1-10 to the unlocked position in which lugs 20 of tumbler discs 2 and 10 are positioned in abutment upon stop portion 68a of the cylinder (see FIG. 15) and in which notches 14 of tumbler discs 1-10 are aligned with slot 70 of the cylinder (see FIG. 16); by inserting locking bar 72 into the groove formed by alignment of notches 14 with slot 70; by loading the cylinder into bore 94 of the barrel so that the threads of collar 54a and 54b mesh with those of intermediate portion 98 of bore 94; by sliding head 86 of the locking member into engagement with rear portion 50 of the cylinder; by turning the key further clockwise to rotate the tumbler discs and, hence, the cylinder engaged by lugs 20 of tumbler discs 2 and relative to the barrel until the externally-threaded collar engaged for rotation with the cylinder is tightly screwed into threaded intermediate portion 98 of bore 94; and by then removing the cylindrical pin from engagement with notch 107a of the externally-threaded collar and hole 107b of the cylinder. Since cylinder 48 may only be rotated clockwise relative to barrel 92 by first turning tumbler discs 1-10 to the unlocked position, the externallythreaded collar engaged for rotation with the cylinder may only be screwed into place with the aid of the key. Once the split externally-threaded collar is screwed into place, the cylinder is held in rotatable driving engagement with the head of the locking member. The key 28 may then be turned counterclockwise to rotate the tumbler discs to the locked position in which the keyholes of the tumbler discs are aligned so that the key may be removed from the lock. Since the first tumbler disc 1 does not have a lug 20, it serves as a freely rotatable spinner when the key is removed. Making the first tumbler disc freely rotatable when the key is removed and providing it with cylindrical front portion 22 of reduced diameter and increased thickness significantly increases the resistance of the lock to drilling, picking, and forcing.

When cylinder 48 is mounted within barrel 92, split externally-threaded collar 54a and 54b is hidden within the barrel behind disc-shaped front portion 56 of the cylinder. Thus, short of destroying the lock, cylinder 48 may only be removed from bore 94 of the barrel by inserting key 28 and turning it clockwise to rotate tumbler discs 1-10 to the unlocked position in which lugs 24a and 24b of the first tumbler disc 1 are aligned with notches 64a and 64b of the cylinder; by pulling the key forward to engage lugs 24a and 24b of the first tumbler disc 1 with notches 64a and 64b of the cylinderand thereby releasably lock the cylinder and tumbler discs for rotation together in either a clockwise or a counterclockwise direction; by turning the key counterclockwise until hole 107b in front portion 56 of the cylinder is aligned with notch 107a in collar portion 540; by inserting a cylindrical pin into aligned hole 107b and notch 1070 to engage the externally-threaded collar for rotation with the cylinder; by turning the key further counterclockwise until the externally-threaded collar is unscrewed from threaded intermediate portion 98 of bore 94; and by sliding the cylinder from bore 94 of the barrel and out of engagement with locking member 84. Since the cylinder may only be rotated counterclockwise relative to the barrel by first turning the tumbler discs to the unlocked position and then pulling the first tumbler disc 1 forward into driving engagement with the cylinder, the externally-threaded collar may only be unscrewed to remove the cylinder from the barrel with the aid. of the key.

As shown in FIGS. 1-3 and 11, barrel 92 also has a pair of oppositely-facing threaded cylindrical outer sides 108, a pair of oppositely-facing flat or otherwise noncircular outer sides 110, and an annular front outer shoulder 112. The assembled lock may therefore be fixedly mounted in a structure 1 14, such as the front panel of a safe deposit box, the door of a vault, or any other structure that must be securely locked, by inserting barrel 92 into a lock opening 116 of the structure and by screwing a threaded mounting nut I18 forward along threaded cylindrical sides 108 of the barrel until the mounting nut and front shoulder 112 of the barrel are tightly drawn into continuous abutment upon opposite sides of the structure. Lock opening 116 may be provided with flat sides corresponding to sides of barrel 92 to prevent the barrel from rotating relative to structure 114. A cylindrical bolt 120 is provided with an internally-threaded end 122 that may be screwed onto partially threaded stem 90 of locking member 84. Cylindrical bolt 120 may be locked against rotation relative to the locking member by screwing a set screw 124 into a correspondingly threaded hole 125 through one side of end 122 of the cylindrical bolt and into abutment upon one of a pair of oppositely-facing flat sides of partially threaded stem 90. By rotating cylinder 48 and, hence, locking member 84 and bolt 120 several complete revolutions in a clockwise direction, a threaded end 126 of the bolt may be screwed into a correspondingly threaded hole in a rear panel 128 to lock structure 1 14 shut against movement relative to the rear panel. Similarly, by rotating cylinder 48 and hence locking member 84 and bolt 120 several turns in a counterclockwise direction, threaded end 126 of the bolt may be unscrewed from hole 130 in rear panel 128 thereby unlocking structure 114 so that it may be opened by moving it relative to the rear panel.

It may sometimes be necessary to remove cylinder 48 from barrel 92, such as, for example, to change the combination of tumbler discs l-l0 in the event one of a set .of keys for the lock is lost. The front-loaded construction of the lock and the manner in which the cylinder is engaged with head 86 of locking member 84 permit the cylinder to be removed from the barrel and subsequently replaced therein without removing the barrel from structure 114 and without removing locking member 84 and bolt 120 from engagement with one another or rear panel 128. This may quickly and simply be accomplished with the aid of a cylindrical pin and the corresponding key, or keys, as described in detail above.

When the assembled lock is locked as shown in FIGS. 2-3 and 11-12 slot 70 of cylinder 48 and slot 106 of barrel 92 are aligned as shown in FIGS. 1, 3 and 11-12. concomitantly, tumbler discs l10 are in the locked position with their keyholes 12 aligned for receiving key 28 as shown in FIG. 1, with lugs 20 of tumbler discs 2-10 aligned in abutment upon stop portion 68b of the cylinder as shown in FIG. 2, with lugs 24a and 24b of the first tumbler disc 1 positioned 90 degrees (as viewed in a clockwise direction) from corresponding notches 64a and 64b of the cylinder and aligned with the common plane of axial symmetry of slots66 and 70 as shown in FIGS. 2-3 and 11-12, and with their notches 14 scrambled as shown in FIG. 3. Locking bar 72 is therefore supported on the circular outer peripheries of tumbler discs l-2, 4, 6, 8, and 10 and, hence, in engagement with slot 70 of the cylinder and groove 106 of the barrel as shown in FIGS. 3 and 11-12. This prevents cylinder 48 and, hence, locking member 84 and bolt 120 from being turned relative to barrel 92, structure 114, and rear panel 128 thereby locking structure 114 shut.

The lock may be unlocked by fully inserting key 28 into aligned keyholes 12 of tumbler discs 1-10 as shown in FIGS. 11-12 and by then turning the key and,

hence, the tumbler discs clockwise relative to the barrel to the unlocked position as shown in FIGS. 13-14. However, since the first tumbler disc 1 is freely rotatable before the key is inserted, the first tumbler disc may not initially be in the locked position even though the lock is locked. The resultant misalignment of keyhole 12 of the first tumbler disc 1 with the aligned keyholes of the adjoining tumbler discs 2-10 then prevents the key from being fully inserted into the lock. In this case, the first tumbler disc 1 may be quickly and simply rotated to the locked position by inserting the key into the keyhole of the first tumbler disc and by then turning the key counterclockwise while applying a slight forward pressure to the key. When the first tumbler disc 1 reaches the locked position in which its keyhole 12 is aligned with the keyholes of the adjoining tumbler discs, the key will then slide forward into engagement with the aligned keyholes of the adjoining tumbler discs and stop the first tumbler disc in the locked position due to the abutment of lugs 20 of the adjoining tumbler discs upon stop portion 68b of the cylinder.

When the assembled lock is unlocked as shown in FIGS. 13-16, tumbler discs 1-10 are in the unlocked position with their keyholes misaligned by the differences between the angles through which they are rotated to the unlocked position thereby preventing the key from being withdrawn from the lock, with lugs 20 of tumbler discs 2-10 similarly misaligned, with lugs 20 of tumbler discs 2 and positioned in abutment upon stop portion 68a of the cylinder as shown in FIG. 15, with lugs 24a and 24b of the first tumbler disc 1 aligned with corresponding notches 64a and 64b of the cylinder as shown in FIGS. 13 and 16, and with their notches 14 aligned with slot 70 of the cylinder and groove 106 of the barrel. If the lock is mounted in structure 114 as shown in FIGS. 11-14, locking bar 72 therefore drops into the groove formed by alignment of notches 14 with slot 70 of the cylinder and, hence, out of engagement with groove 106 of the barrel. Even if the lock is mounted upside down in structure 114 from the position shown in FIGS. ll-14, locking bar 72 is forced into the groove formed by alignment of notches 14 with slot 70 and out of engagement with groove 106 as the key is turned further clockwise. This occurs because abutment of lugs of tumbler discs 2 and 10 upon stop portion 68a of the cylinder causes the cylinder and tumbler discs to rotate together relative to the barrel as the key is turned further clockwise, thereby causing the back side of slot 70 to abut upon locking bar 72 and force it out of engagement with groove 106 and into the groove formed by alignment of notches 14 with slot 70. A locking bar spring loaded outwardly against the inner wall of the barrel may therefore be employed in place of locking bar 72. Alternatively, a locking bar spring loaded inwardly toward the tumbler discs as shown, for example, in the aforementioned U. S. Pat. No. 2,217,047 may be employed so that it is automatically forced intothe groove formed by alignment of notches 14 with slot 70 no matter what position the lock may be in. In any event, once the assembled lock is unlocked, cylinder 48 and, hence, locking member 84 and bolt 120 may be freely rotated clockwise with the key relative to barrel 92.

Once the lock is unlocked, lugs 24a and 24b of the first tumbler disc I are maintained in alignment with corresponding notches 64a and 64b of the cylinder as the key is turned further clockwise since, as explained above, the cylinder and tumbler discs rotate together as the key is turned further in this direction. Whenever the lock is unlocked, the key is prevented from being withdrawn from the lock by misalignment of keyholes 12 and, hence, by abutment of driving portions 34, 36, 38, and 40 of the key upon the adjoining tumbler discs 3, 5, 7, and 9, respectively, as the key is pulled forward. Lugs 24a and 24b of the first tumbler disc 1 may therefore be engaged with corresponding notches 64a and 64b of the cylinder by simply pulling the key forward as shown in FIG. 17. This engages the first tumbler disc 1 for rotation with the cylinder and thereby locks all of the tumbler discs in the unlocked position for rotation with the cylinder so that the cylinder and, hence, locking member 84 and bolt 120 may be freely rotated either clockwise or counterclockwise with the key relative to barrel 92 as shown in FIGS. 17-19. Bolt 120 may therefore be unscrewed from rear panel 128 to unlock structure 114 for movement relative to rear panel 128 by turning the key counterclockwise to rotate the cylinder a plural number of revolutions counterclockwise. Similarly, bolt 120 may be screwed back into rear panel 128 to lock structure 114 shut again by turning the key clockwise to rotate the cylinder clockwise the same number of revolutions as it was rotated counterclockwise to unlock structure 114.

Lugs 24a and 24b of the first tumbler disc I may be disengaged from notches 64a and 64b of the cylinder by simply pushing the key backward since the circular intermediate portion 42 of the key abuts upon cylindrical portion 22 of the first tumbler disc 1 as the key is pushed backward. The lock may thereupon be locked again by turning the key counterclockwise to rotate tumbler discs l-10 counterclockwise toward their locked position. As the tumbler discs are rotated counterclockwise, locking bar 72 is urged outwardly toward barrel 92 by abutment of the curved and inclined trailing sides (as viewed in a counterclockwise direction) of aligned notches 14 but is held in engagement with aligned notches 14 and slot by abutment upon the wall of bore 94 of the barrel. Cylinder 48 therefore rotates with tumbler discs 1-10 until slot 70 of the cylinder is rotated into alignment with groove 106 of the barrel. Locking bar 72 thereupon rides up the inclined trailing sides of notches 14 of tumbler discs 1 and 10 and into engagement with groove 106 of the barrel thereby preventing the cylinder from rotating any further counterclockwise with the tumbler discs. Thus, when the tumbler discs are rotated degrees further counterclockwise, they are again in their locked position and the lock locked as shown in FIGS. 2-3 and ll-I2 and described in detail above thereby permitting the key to be withdrawn from the lock.

Referring now to FIGS. 20-25, there is shown a disc and sidebar cylinder lock and key according to another of the preferred embodiments of this invention. As shown in FIGS. 20-24, this lock includes a plurality of tumbler discs 201-209 similar to those of the lock described above. Each of these tumbler discs has a semicircular keyhole 212, a circular outer periphery with a notch 214 therein, and a radial lug 216. Notches 214 are generally rectangular with their sides inclined at an angle of about 45 degrees but may also be round 13 as described above in connection with FIG. 4. They are arranged in a selected combination of six different positions equally spaced along an arc of 90 degrees so that they may be brought into alignment by simply rotating each of the tumbler discs 201-209 through an angle of from to 90 degrees.

Tumbler discs 201-209 have a locked position at which semicircular keyholes 212 and lugs 216 are aligned as shown in FIGS. and 22 and notches 214 are scrambled as shown in FIG. 21. They also have an unlocked position at which keyholes 212 and lugs 216 are misaligned as shown in FIG. 23 and notches 214 are unscrambled and aligned as shown in FIG. 24. For the combination of notch positions illustrated in FIG. 21, tumbler discs 201-209 may be rotated from the locked to the unlocked position by rotating tumbler discs 201, 202, and 209 clockwise through an angle of 90, rotating tumbler discs 203 and 208 clockwise through an angle of 72, rotating tumbler disc 207 clockwise through an angle of 54, rotating tumbler disc 206 clockwise through an angle of 36, rotating tumbler disc 205 clockwise through an angle of 18, and rotating tumbler disc 204 clockwise through an angle of 0. Similarly, tumbler discs 201-209 may be rotated from the unlocked position to the locked position by rotating them counterclockwise through the same angles.

Tumbler discs 201-209 are turned between the locked and unlocked positions under the control of a key 218. As shown in FIGS. 20 and 25, key 218 has a flattened generally loop-shaped end section 219 to facilitate holding and turning the key. It also has a straight end section 220 with a generally semicircular cross section corresponding to that of keyholes 212, a

plurality of different driving portions 221-229 corresponding in order to tumbler discs 201-209, and a stop 230 positioned for abutment upon the first tumbler disc 201 when straight end section 220 is fully inserted into all of the keyholes. Driving portions 221-229 of the key are angularly coded for driving the corresponding tumbler discs 201-209 between the locked and unlocked positions as the key is turned through an angle of ninety degrees. As shown in FIG. this is accomplished for the combination of notch positions illustrated in FIG. 21 by providing driving portions 221-229 with a common radial rear driving surface (1,, providing driving portions 221, 222, and 229 with a radial front driving surface d, forming a pick-up angle of 0, providing driving portions 223 and 228 with a front driving surface d forming a pick-up angle of 18, providing driving portion 227 with a front driving surface 41;, forming a pick-up angle of 36, providing driving portion 226 with a front driving surface d forming a pick-up angle of 54, providing driving portion 225 with a front driving surface d forming a pick-up angle of 72, and providing driving portion 224 with a front driving surface d forming a pick-up angle of 90. As described above in connection with FIGS. 7-8, the pick-up angle is the angle the radial front driving surface of each driving portion makes with respect to the plane of radial rear driving surface d and is made equal to the complement of the angle through which the corresponding tumbler disc must be rotated between the locked and unlocked positions.

As shown in FIGS. 20, 21, and 24, a cylinder 234 is provided with a smooth axial bore 236 for rotatably supporting tumbler discs 201-209. This bore is open at the front for receiving the tumbler discs and is closed at the back by an end wall 238 having a concentric cylindrical recess 240 of smaller diameter for receiving the tip of straight end section 220 of the key. End wall 238 is formed integrally with a rotary locking member such as a cam or a partially threaded lug 241 of reduced diameter. A slot 242 for receiving lugs 216 of tumbler discs 201-209 extends through one side of cylinder 234 along the full length of bore 236. The edges 244a and 244b of slot 242 are angularly spaced apart to serve as stops for limiting lugs 216 and, hence, tumbler discs 201-209 to rotation through a maximum angle of ninety degrees relative to cylinder 234. Another slot 246 for receiving a locking bar 248 extends through the opposite side of cylinder 234 along the full length of bore 236. Slots 242 and 246 are arranged so that when tumbler discs 201-209 are loaded into bore 236 and rotated to the locked position lugs 216 are aligned in abutment upon edge 244b of slot 242 as shown in FIG. 22 and notches 214 are scrambled as shown in FIG. 21, and so that when the tumbler discs are rotated to the unlocked position lugs 216 of tumbler discs 201 202 and 209 are aligned in abutment upon edge 2440 of slot 242 as shown in FIG. 23 and notches 214 are aligned with slot 246 to form a groove for receiving locking bar 248 as shown in FIG. 24. Locking bar 248 has a diameter substantially equal to, 'but not greater than, the depth of the groove formed by alignment of notches 214 with slot 246 so that the locking bar protrudes from slot 246 when it is supported on the circular outer peripheries of the tumbler discs but not when it is supported in the aligned notches 214.

Tumbler discs 201-209 are separated from one another by annular spring washers 250 of the same outer diameter as the tumbler discs and are loaded with these spring washers into bore 236 through the open front end thereof. Annular spring washers 250 are each provided with a generally circular central opening that is larger than semicircular keyholes 212 so as not to interfere with rotational or axial movement of straight end section 220 of key 218, with a radial lug 252 that is fixedly engaged between edges 244a and 244b of slot 242 so as to prevent the rotational movement of any tumbler disc from being transmitted to the other tumbler discs, and with a notch 254 that is aligned with slot 246 and made as large or larger than notches 214 so as not to interfere with movement of locking bar 248 into notches 214 when they are aligned with slot 246. Once tumbler discs 201-209 and annular spring washers 250 are loaded into bore 236 of the cylinder, a stop disc 256 of the same outer diameter as the cylinder is positioned in abutment upon the open front end of the cylinder. This stop disc is provided with a circular central opening of the same diameter as semicircular keyholes 212, with a lateral lug 258 thatabuts upon edge 244b of slot 242 and upon lug' 216 of the first tumbler disc 201 as shown in FIG. 22, and with another lateral lug 260, that is fixedly engaged in slot 246 as shown in FIGS. 21 and 24 to prevent the stop disc from rotating relative to the cylinder. As shown in FIGS. 22 and 23, a gap is provided between lug 258 of stop disc 256 and edge 244a of slot 242. This gap is positioned for receiving lug 216 of the first tumbler disc 201 when the tumbler discs are rotated to the unlocked position.

As shown in FIGS. 20, 21, and 24, an outer casing or barrel 262 is provided with a smooth axial bore 263 for rotatably supporting stop disc 256 and cylinder 234. This bore is open at the back for receiving stop disc 256 and cylinder 234 and is closed at the front by an end wall 264 with a concentric circular opening 266 of the same diameter as semicircular keyholes 212. A groove 268 is formed in the wall of bore 263 along substantially the full length thereof to a depth about equal to the radius, but less than the diameter, of locking bar 248. Groove 268 is positioned for alignment with slot 246 of the cylinder to provide a channel for receiving the locking bar when it is supported on the circular outer peripheries of the tumbler discs.

Cylinder 234 and stop disc 256 are mounted within bore 263 of barrel 262 by rotating tumbler discs 201-209 to the locked position; by placing locking bar 248 in slot 246 of the cylinder and, hence, upon the circular outer peripheries of tumbler discs 201-203 and 205-209; by aligning locking bar 248 and slot 246 with groove 268 of the barrel and thereupon loading the stop disc, cylinder, and locking bar into bore 263 of the barrel; by pushing the cylinder forward sothat it is fully engaged with the stop disc and so that the tumbler discsare slightly spring biased by spring washers 250 against lateral lug 258 of the stop disc; and by seating a spring clip 269 in a groove in the wall of bore 263 toward the open back end thereof and in abutment upon the back end of the cylinder to hold the stop disc and cylinder in place as shown in FIGS. 21 and 24. An annular crown spring, or some other such spring loading device, may be employed between the last tumbler disc 209 and end wall 238 of the cylinder in place of the last spring washer 250 to spring bias tumbler discs 201-209 against lateral lug 258 of stop disc 256. This annular crown spring may be employed together with spring washers 250 or alone for this purpose. In the latter case, spring washers 250 may be replaced by similar washers not of a spring type. (Tumbler discs 1-10 of the lock of FIGS. 1-19 may also be spring loaded in any of the ways described above. Barrel 262 is provided with a pair of oppositely-facing threaded outer sides 270, a pair of oppositely-facing flat sides 272, and an annular front shoulder 274 so that the assembled lock may be mounted in a structure, such as a coin box or some other structure to be locked, in the same manner as shown and described above in connection with FIG. 1 1.

When the assembled lock. is locked, slot 246 of cylinder 234 is aligned with groove 268 of barrel 262 as shown in FIG. 21. Concomitantly, tumbler discs 201-209 are in the locked position with their keyholes 212 aligned for receiving key 218 as shown in FIG. 20,

with their lugs 216 aligned in abutment upon stop portion 244b of the cylinder as shown in FIG. 22, and with their notches 214 scrambled as shown in FIG. 21'. Locking bar 248 is therefore supported on the circular outer peripheries of tumbler discs 201-203 and 205-209 and, hence, in engagement with slot 246 of the cylinder and groove 268 of the barrel. This prevents cylinder 234 and threaded locking lug 241 from being turned relative to the barrel.

The lock may be unlocked by fully inserting key 218 into aligned keyholes 212 of tumbler discs 201-209 and turning it ninety degrees clockwise relative to the barrel. This rotates the tumbler discs to the unlocked position with their keyholes 212 misaligned by the differences between the angles through which they are rotated to the unlocked position (thereby preventing key 218 from being withdrawn from the lock), with their lugs 216 similarly misaligned, with lugs 216 of tumbler discs 201, 202, and 209 positioned in abutment upon stop portion 244a of the cylinder as shown in FIG. 23, with lug 216 of the first tumbler disc 201 antomatically spring biased into engagement with the gap between lug 258 of stop disc 256 and stop portion 244a of the cylinder as shown in FIG. 23 (thereby locking the tumbler discs in the unlocked position for rotation with the cylinder), and with notches 214 aligned with slot 246 of the cylinder and groove 268 of the barrel as shown in FIG. 24. Thus, depending upon the orientation of the lock, locking bar 248 either drops, or is forced as the key is turned further clockwise or counterclockwise, into the groove formed by alignment of notches 214 of the tumbler discs with slot 246 of the cylinder and, hence, out of engagement with groove 268 of the barrel. Cylinder 234 and threaded locking lug 241 may therefore be freely rotated either clockwise or counterclockwise with the key relative to barrel 262 once the lock is unlocked.

Since stop 230 of the key abuts upon the front face of the first tumbler disc 201 when the key is fully inserted into keyholes 212 of the tumbler discs, lug 216 of the first tumbler disc 201 may be disengaged from the gap between lug 258 of stop disc 256 and stop portion 244a of cylinder- 234 by simply pushing key 218 backward and turning the key counterclockwise. The lock may thereupon be locked again by turning the key further counterclockwise to rotate the tumbler discs toward their locked position. As the tumbler discs are rotated counterclockwise, locking bar 248 is urged outwardly toward barrel 262 by abutment of the inclined trailing sides (as viewed in a counterclockwise direction) of aligned notches 214 but is held in engagement with aligned notches 214 and slot 246 by abutment upon the wall of bore 263 of the barrel. Cylinder 234 therefore rotates with tumbler discs 201-209 until slot 246 of the cylinder is rotated into alignment with groove 268 of the barrel. Locking bar 248 thereupon rides up the inclined'trailing sides of notches 214 of tumbler discs 201, 202, and 209 and into engagement with groove 268 of the barrel thereby preventing the cylinder from rotating any further counterclockwise with the tumbler discs. Thus, when the tumbler discs are rotated ninety degrees further counterclockwise, they are returned to their locked position as shown in FIGS. 21-22 and described in detail above thereby locking the lock and permitting the key to be withdrawn from the lock.

I claim:

1. A cylinder lock comprising:

an outer casing having a cavity therein;

a cylinder rotatably supported within the cavity of the outer casing, said cylinder having a cavity therein and having a slot communicating with the cavity therein;

a plurality of key-controlled tumbler discs supported within the cavity of the cylinder for rotation therein between locked and unlocked positions, said tumbler discs each having a notch therein for alignment with the slot in the cylinder when the tumbler discs are in the unlocked position;

a locking bar supported on the outer peripheries of one or more of the tumbler discs and in engagement with the outer casing and the slot in the cylinder when the tumbler discs are in the locked position to prevent the cylinder from rotating relative to the outer casing, the notches in the tumbler discs being aligned with the slot in the cylinder when the tumbler discs are in the unlocked position to form a groove for receiving the locking bar to permit rotation of the cylinder relative to the outer casing; and

means for releasably engaging the cylinder for bidirectional rotation with the tumbler discs when they are in the unlocked position to permit rotation of the cylinder andtumbler discs together more than one complete revolution in opposite directions relative to the outer casing, said means comprising part of one of the tumbler discs having an angle of rotation between the locked and unlocked positions at least as great as that of any of the other tumbler discs, said part being axially movable into fixed engagement with the cylinder when the tumbler discs are in the unlocked posi-r tion.

2. A cylinder lock as in claim 1 wherein:

said part of one of the tumbler discs comprises a lug positioned on the front face of the first tumbler disc;

said means further comprises a notch positioned in the cylinder for alignment with the lug on the front face of the first tumbler disc when the tumbler discs are in the unlocked position; and

said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lug on the front face of the first tumbler disc with the notch in the cylinder.

3. A cylinder lock as in claim 1 wherein:

said part of one of the tumbler discs comprises a lug positioned on the periphery of the first tumbler disc;

said means further comprises a stop member engaged for rotation with the cylinder and positioned in abutment upon the front end thereof, said stop member including a stop portion spaced apart from a stop portion of the cylinder to provide a gap for alignment with the lug on the periphery of the first tumbler disc when the tumbler discs are in the unlocked position; and

said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lug on the periphery of the first tumbler disc with'the gap between the stop portion of the stop member and the stop portion of the cylinder.

4. A cylinder lock as in claim 1 wherein the first tumbler disc is freely rotatable within the cylinder when not engaged by a key for the lock and is provided with a concentric cylindrical front portion of reduced diameter and increased thickness communicating with the front of the outer casing.

5. A cylinder lock as in claim 1 wherein: said cavity of the outer casing communicates with the front of the outer casing and includes a threaded intermediate portion; and

said cylinder is loaded into the cavity of the outer casing through the front end thereof and is held in place by a split extemally-threaded collar supported around a neck-like intermediate portion of the cylinder and screwed into the threaded intermediate portion of the cavity of the outer casing.

6. A cylinder lock as in claim 1 wherein:

said cavity of the outer casing comprises an axial cylindrical bore for rotatably supporting the cylinder;

said outer casing has a groove extending along the axial cylindrical bore thereof;

said cavity of the cylinder comprises an axial cylindrical bore for rotatably supporting the tumbler discs;

said slot of the cylinder extends along the axial cylindrical bore of the cylinder and is positioned for alignment with the groove in the outer casing;

said tumbler discs are spaced apart from one another within the axial cylindrical bore of the cylinder, one or more of said tumbler discs having a stop portion for abutting upon a first stop portion of the cylinder when the tumbler discs are in the locked position and upon a second stop portion of the cylinder when the tumbler discs are in the unlocked position to limit the tumbler discs to key controlled rotation between their locked and-unlocked positions relative to the cylinder;

said notches in the tumbler discs are arranged for .alignment with the slot in the cylinder and the groove in the outer casing when the tumbler discs are in the unlocked position;

said locking bar is supported on the outer peripheries of one or more of the tumbler discs and in engagement with the slot in the cylinder and the groove in the outer casing when the tumbler discs are in the locked position to prevent the cylinder from rotating relative to the outer casing, the notches in the tumbler discs being aligned with the slot in the cylinder when the tumbler discs are in the unlocked position to form a groove for receiving the locking bar out of engagement with the groove in the outer casing to permit rotation of the cylinder relative tothe outer casing; and

said part of one of the tumbler discs is axially movable into fixed engagement with the cylinder when the tumbler discs are in the unlocked position to permit rotation of the cylinder and tumbler discs together a plural number of complete revolutions in opposite directions relative to the outer casing.

7. A cylinder lock as in claim 6 wherein:

said part of one of the tumbler discs comprises a lug positioned on the front face of the first tumbler disc;

said means further comprises a notch positioned in the cylinder for alignment with the lug on the front face of the first tumbler disc when the tumbler discs are in the unlocked position; and

said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lug on the front face of the first tumbler disc with the notch in the cylinder.

8. A cylinder lock as in claim 7 wherein the first tumbler disc is freely rotatable within the cylinder when not engaged with a key for the lock and is provided with a concentric cylindrical front portion of reduced diameter and increased thickness communicating with the front of the outer casing.

9. A cylinder lock as in claim 8 wherein:

said part of the first tumbler disc comprises a pair of lugs positioned on the front face of the first tumbler disc adjacent to diametrically opposite sides of the cylindrical front portion of the first tumbler disc;

said means comprises a pair of notches positioned in the cylinder for alignment with the pair of lugs on the front face of the first tumbler disc when the tumbler discs are in the unlocked position; and

said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lugs on the front face of the first tumbler disc with the notches in the cylinder.

10. A cylinder lock as in claim 9 wherein the notch in the first tumbler disc has an inclined side for lifting the locking bar out of engagement with the notches in the tumbler discs and into engagement with the groove in the outer casing as the tumbler discs are rotated from the unlocked position to the locked position.

11. A cylinder lock as in claim 9 wherein:

said axial cylindrical bore of the outer casing communicates with the front of the outer casing and includes a threaded intermediate portion; and

said cylinder is loaded into the axial cylindrical bore of the outer casing through the front end thereof and is held in place by a split externally-threaded collar supported around a neck-like intermediate portion of the cylinder and screwed into the threaded intermediate portion of the outer casing.

12. A cylinder lock as in claim 11 wherein a hole extends through. a front portion of the cylinder and is positioned for alignment with a notch in the split externally-threaded collar so that a pin may be inserted through the hole in the front portion of the cylinder and into the notch in the collar to engage the split externally-threaded collar for rotation with the cylinder and thereby permit the split externally-threaded collar to be unscrewed from the threaded intermediate portion of the outer casing with the aid of a key for the look when the tumbler discs are rotated to the unlocked position and engaged for rotation with the cylinder.

13. A cylinder lock as in claim 12 wherein:

said axial cylindrical bore of the cylinder extends through a rear portion of the cylinder and communicates with an opening of smaller diameter that extends through the back end of the outer casing; and

a locking member is provided with a head axially slidably positioned in the back end of the axial cylindrical bore of the cylinder and engaged between the first and second stop portions of the cylinder for rotation with the cylinder, said locking member being further provided with a rotary locking portion that protrudes through the opening in the back end of the outer casing.

14. A cylinder lock as in claim 13 wherein:

said first tumbler disc may be axially pulled forward by a key for the lock when the tumbler discs are in the unlocked position to engage the lugs on the front face of the first tumbler disc with the notches in the cylinder; and

said first tumbler disc may be axially pushed backward by a key for the lock to disengage the lugs on the front face of the first tumbler disc from the notches in the cylinder.

15. A cylinder lock as in claim 13 wherein:

said first tumbler disc is spring biased so that it automatically moves axially forward to engage the lugs on its front face with the notches in the cylinder when the tumbler discs are in the unlocked position; and

said first tumbler disc may be axially pushed backward and rotated toward the locked position by a key for the lock to disengage the lugs on the front face of the first tumbler disc from the notches in the cylinder.

16. A cylinder lock as in claim 6 wherein:

said part of one of the tumbler discs comprises a lug positioned on the periphery of the first tumbler disc;

said means further comprises a stop member engaged for rotation with the cylinder and positioned in abutment upon the front end thereof, said stop member including a first stop portion positioned in abutment upon the first stop portion of the cylinder and a second stop portion spaced apart from the second stop portion of the cylinder to provide a gap for alignment with the lug on the periphery of the first tumbler disc when the tumbler discs are in the unlocked position; and

said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lug on the periphery of the first tumbler disc with the gap between the second stop portion of the stop member and the second stop portion of the cylinder.

17. A cylinder lock as in claim 16 wherein:

said first tumbler disc'is spring biased so that it automatically moves axially forward to engage the lug on its periphery with the gap between the second stop portion of the stop member and the second stop portion of the cylinder when the tumbler discs are in the unlocked position; and

said first tumbler disc may be axially pushed backward and rotated toward the locked position by a key for the lock to disengage the lug on the periphery of the first tumbler disc from the gap between the second stop portion of the stop member and the second stop portion of the cylinder.

18. A cylinder lock comprising:

an outer casing having a cavity therein;

a cylinder rotatably supported within the cavity of A the outer casing, said cylinder having a cavity therein and having a slot communicating with the cavity therein;

a plurality of key-controlled tumbler discs supported within the cavity of the cylinder for rotation therein between locked and unlocked positions, said tumbler discs each having a notch therein for alignment with the slot in the cylinder when the tumbler discs are in the unlocked position;

a locking bar supported on the outer peripheries of one or more of the tumbler discs and in engagement with the outer casing and the slot in the cylinder when the tumbler discs are in the locked position to prevent the cylinder from rotating relative to the outer casing, the notches in the tumbler 22. comprising a key-controlled member having an angle of rotation between the locked and unlocked positions of the tumbler discs at least as great as that of any of the tumbler discs.

discs being aligned with the slot in the cylinder when the tumbler discs are in the unlocked position to form a groove for receiving the locking bar to permit rotation of the cylinder relative to the outer casing; and

means for releasably engaging the cylinder for 1 bidirectional rotation with the tumbler discs when they are in the unlocked position to permit rota- 19. A cylinder lock as in claim 18 wherein said keycontrolled member is axially movable into fixed engagement with the cylinder when the tumbler discs are in the unlocked position.

20. A cylinder lock as in claim 19 wherein said keycontrolled member comprises one of the tumbler discs having a portion axially movable into fixed engagement tion of the cylinder and tumbler discs together with the cylinder when the tumbler discs are in the unmore than one complete revolution in opposite locked posmon' directions relative to the outer casing, said means 

1. A cylinder lock comprising: an outer casing having a cavity therein; a cylinder rotatably supported within the cavity of the outer casing, said cylinder having a cavity therein and having a slot communicating with the cavity therein; a plurality of key-controlled tumbler discs supported within the cavity of the cylinder for rotation therein between locked and unlocked positions, said tumbler discs each having a notch therein for alignment with the slot in the cylinder when the tumbler discs are in the unlocked position; a locking bar supported on the outer peripheries of one or more of the tumbler discs and in engagement with the outer casing and the slot in the cylinder when the tumbler discs are in the locked position to prevent the cylinder from rotating relative to the outer casing, the notches in the tumbler discs being aligned with the slot in the cylinder when the tumbler discs are in the unlocked position to form a groove for receiving the locking bar to permit rotation of the cylinder relative to the outer casing; and means for releasably engaging the cylinder for bidirectional rotation with the tumbler discs when they are in the unlocked position to permit rotation of the cylinder and tumbler discs together more than one complete revolution in opposite directions relative to the outer casing, said means comprising part of one of the tumbler discs having an angle of rotation between the locked and unlocked positions at least as great as that of any of the other tumbler discs, said part being axially movable into fixed engagement with the cylinder when the tumbler discs are in the unlocked position.
 2. A cylinder lock as in claim 1 wherein: said part of one of the tumbler discs comprises a lug positioned on the front face of the first tumbler disc; said means further comprises a notch positioned in the cylinder for alignment with the lug on the front face of the first tumbler disc when the tumbler discs are in the unlocked position; and said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lug on the front face of the first tumbler disc with the notch in the cylinder.
 3. A cylinder lock as in claim 1 wherein: said part of one of the tumbler discs comprises a lug positioned on the periphery of the first tumbler disc; said means further comprises a stop member engaged for rotation with the cylinder and positioned in abutment upon the front end thereof, said stop member including a stop portion spaced apart from a stop portion of the cylinder to provide a gap for alignment with the lug on the periphery of the first tumbler disc when the tumbler discs are in the unlocked position; and said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the luG on the periphery of the first tumbler disc with the gap between the stop portion of the stop member and the stop portion of the cylinder.
 4. A cylinder lock as in claim 1 wherein the first tumbler disc is freely rotatable within the cylinder when not engaged by a key for the lock and is provided with a concentric cylindrical front portion of reduced diameter and increased thickness communicating with the front of the outer casing.
 5. A cylinder lock as in claim 1 wherein: said cavity of the outer casing communicates with the front of the outer casing and includes a threaded intermediate portion; and said cylinder is loaded into the cavity of the outer casing through the front end thereof and is held in place by a split externally-threaded collar supported around a neck-like intermediate portion of the cylinder and screwed into the threaded intermediate portion of the cavity of the outer casing.
 6. A cylinder lock as in claim 1 wherein: said cavity of the outer casing comprises an axial cylindrical bore for rotatably supporting the cylinder; said outer casing has a groove extending along the axial cylindrical bore thereof; said cavity of the cylinder comprises an axial cylindrical bore for rotatably supporting the tumbler discs; said slot of the cylinder extends along the axial cylindrical bore of the cylinder and is positioned for alignment with the groove in the outer casing; said tumbler discs are spaced apart from one another within the axial cylindrical bore of the cylinder, one or more of said tumbler discs having a stop portion for abutting upon a first stop portion of the cylinder when the tumbler discs are in the locked position and upon a second stop portion of the cylinder when the tumbler discs are in the unlocked position to limit the tumbler discs to key-controlled rotation between their locked and unlocked positions relative to the cylinder; said notches in the tumbler discs are arranged for alignment with the slot in the cylinder and the groove in the outer casing when the tumbler discs are in the unlocked position; said locking bar is supported on the outer peripheries of one or more of the tumbler discs and in engagement with the slot in the cylinder and the groove in the outer casing when the tumbler discs are in the locked position to prevent the cylinder from rotating relative to the outer casing, the notches in the tumbler discs being aligned with the slot in the cylinder when the tumbler discs are in the unlocked position to form a groove for receiving the locking bar out of engagement with the groove in the outer casing to permit rotation of the cylinder relative to the outer casing; and said part of one of the tumbler discs is axially movable into fixed engagement with the cylinder when the tumbler discs are in the unlocked position to permit rotation of the cylinder and tumbler discs together a plural number of complete revolutions in opposite directions relative to the outer casing.
 7. A cylinder lock as in claim 6 wherein: said part of one of the tumbler discs comprises a lug positioned on the front face of the first tumbler disc; said means further comprises a notch positioned in the cylinder for alignment with the lug on the front face of the first tumbler disc when the tumbler discs are in the unlocked position; and said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lug on the front face of the first tumbler disc with the notch in the cylinder.
 8. A cylinder lock as in claim 7 wherein the first tumbler disc is freely rotatable within the cylinder when not engaged with a key for the lock and is provided with a concentric cylindrical front portion of reduced diameter and increased thickness communicating with the front of the outer casing.
 9. A cylinder lock as in claim 8 wherein: said part of the first tumbler disc comprises a pair of lugs positioned on the front face of the first Tumbler disc adjacent to diametrically opposite sides of the cylindrical front portion of the first tumbler disc; said means comprises a pair of notches positioned in the cylinder for alignment with the pair of lugs on the front face of the first tumbler disc when the tumbler discs are in the unlocked position; and said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lugs on the front face of the first tumbler disc with the notches in the cylinder.
 10. A cylinder lock as in claim 9 wherein the notch in the first tumbler disc has an inclined side for lifting the locking bar out of engagement with the notches in the tumbler discs and into engagement with the groove in the outer casing as the tumbler discs are rotated from the unlocked position to the locked position.
 11. A cylinder lock as in claim 9 wherein: said axial cylindrical bore of the outer casing communicates with the front of the outer casing and includes a threaded intermediate portion; and said cylinder is loaded into the axial cylindrical bore of the outer casing through the front end thereof and is held in place by a split externally-threaded collar supported around a neck-like intermediate portion of the cylinder and screwed into the threaded intermediate portion of the outer casing.
 12. A cylinder lock as in claim 11 wherein a hole extends through a front portion of the cylinder and is positioned for alignment with a notch in the split externally-threaded collar so that a pin may be inserted through the hole in the front portion of the cylinder and into the notch in the collar to engage the split externally-threaded collar for rotation with the cylinder and thereby permit the split externally-threaded collar to be unscrewed from the threaded intermediate portion of the outer casing with the aid of a key for the lock when the tumbler discs are rotated to the unlocked position and engaged for rotation with the cylinder.
 13. A cylinder lock as in claim 12 wherein: said axial cylindrical bore of the cylinder extends through a rear portion of the cylinder and communicates with an opening of smaller diameter that extends through the back end of the outer casing; and a locking member is provided with a head axially slidably positioned in the back end of the axial cylindrical bore of the cylinder and engaged between the first and second stop portions of the cylinder for rotation with the cylinder, said locking member being further provided with a rotary locking portion that protrudes through the opening in the back end of the outer casing.
 14. A cylinder lock as in claim 13 wherein: said first tumbler disc may be axially pulled forward by a key for the lock when the tumbler discs are in the unlocked position to engage the lugs on the front face of the first tumbler disc with the notches in the cylinder; and said first tumbler disc may be axially pushed backward by a key for the lock to disengage the lugs on the front face of the first tumbler disc from the notches in the cylinder.
 15. A cylinder lock as in claim 13 wherein: said first tumbler disc is spring biased so that it automatically moves axially forward to engage the lugs on its front face with the notches in the cylinder when the tumbler discs are in the unlocked position; and said first tumbler disc may be axially pushed backward and rotated toward the locked position by a key for the lock to disengage the lugs on the front face of the first tumbler disc from the notches in the cylinder.
 16. A cylinder lock as in claim 6 wherein: said part of one of the tumbler discs comprises a lug positioned on the periphery of the first tumbler disc; said means further comprises a stop member engaged for rotation with the cylinder and positioned in abutment upon the front end thereof, said stop member including a first stop portion positioned in abutment upon the first stop portion of the cylinder and a second stop portion spAced apart from the second stop portion of the cylinder to provide a gap for alignment with the lug on the periphery of the first tumbler disc when the tumbler discs are in the unlocked position; and said first tumbler disc is axially movable within the cylinder when the tumbler discs are in the unlocked position to engage the lug on the periphery of the first tumbler disc with the gap between the second stop portion of the stop member and the second stop portion of the cylinder.
 17. A cylinder lock as in claim 16 wherein: said first tumbler disc is spring biased so that it automatically moves axially forward to engage the lug on its periphery with the gap between the second stop portion of the stop member and the second stop portion of the cylinder when the tumbler discs are in the unlocked position; and said first tumbler disc may be axially pushed backward and rotated toward the locked position by a key for the lock to disengage the lug on the periphery of the first tumbler disc from the gap between the second stop portion of the stop member and the second stop portion of the cylinder.
 18. A cylinder lock comprising: an outer casing having a cavity therein; a cylinder rotatably supported within the cavity of the outer casing, said cylinder having a cavity therein and having a slot communicating with the cavity therein; a plurality of key-controlled tumbler discs supported within the cavity of the cylinder for rotation therein between locked and unlocked positions, said tumbler discs each having a notch therein for alignment with the slot in the cylinder when the tumbler discs are in the unlocked position; a locking bar supported on the outer peripheries of one or more of the tumbler discs and in engagement with the outer casing and the slot in the cylinder when the tumbler discs are in the locked position to prevent the cylinder from rotating relative to the outer casing, the notches in the tumbler discs being aligned with the slot in the cylinder when the tumbler discs are in the unlocked position to form a groove for receiving the locking bar to permit rotation of the cylinder relative to the outer casing; and means for releasably engaging the cylinder for bidirectional rotation with the tumbler discs when they are in the unlocked position to permit rotation of the cylinder and tumbler discs together more than one complete revolution in opposite directions relative to the outer casing, said means comprising a key-controlled member having an angle of rotation between the locked and unlocked positions of the tumbler discs at least as great as that of any of the tumbler discs.
 19. A cylinder lock as in claim 18 wherein said key-controlled member is axially movable into fixed engagement with the cylinder when the tumbler discs are in the unlocked position.
 20. A cylinder lock as in claim 19 wherein said key-controlled member comprises one of the tumbler discs having a portion axially movable into fixed engagement with the cylinder when the tumbler discs are in the unlocked position. 